Method for manufacturing a laminated log and the laminated log

ABSTRACT

A method for manufacturing a laminated log having a solid insulating material layer located between internal and external plank layers of natural wood, with a plurality of compression limiter members located into respective through hole extending through the solid insulating material layer and extending between the internal and external layers to control and preferably prevent excessive compression of the insulating member during the bonding under relatively high pressure of all layers at the same time. After the layers are bonded, the laminated log typically runs through a molder device which gives the exterior surface a rounded edge to make it look like a natural log. The log manufactured using the above method is also part of the present invention.

CROSS REFERENCE TO RELATED APPLICATIONS

Benefit of priority of UK Patent Application Serial No. GB1307158.4, filed on Apr. 19, 2013, incorporated herein by reference, is hereby claimed.

FIELD OF THE INVENTION

The present invention relates generally to laminated logs, and more particularly to a laminated log and an improved method for manufacturing the laminated log used for building houses and the like.

BACKGROUND OF THE INVENTION

There is a market for those who love the rustic look of a log cabin,

Unfortunately, because of the cost of full tree trunks, many have opted for laminated log cabins. Often times, these laminated logs include an insulating material such as Styrofoam™ or polyurethane combined to the wood element, in order to provide a humidity barrier between the interior and exterior sides, with good insulation. Also, in order to prevent delamination of the laminated log under relatively high temperature and humidity level gradients across the log, the manufacturing of these laminated logs require extensive steps which lead to an expensive cost of the logs. Typically, wooden planks are first laminated together at a relatively higher pressure than the pressure required to laminate the insulating material to the wooden planks since the insulating material cannot sustain high pressure without losing its insulating properties, such that the lamination process of a laminated log is performed in successive lamination steps, at different pressure levels for each step, and thus involving higher manufacturing costs.

Accordingly, there is a need for an improved laminated log and method for manufacturing the same.

SUMMARY OF THE INVENTION

It is therefore a general object of the present invention to provide an improved laminated log and method for manufacturing the same.

An advantage of the present invention is to provide for a better way to laminate wood to an insulating material, and therefore manufacturing the laminated logs, typically using compression limiter members extending through the insulating material to control, and preferably prevent, its compression during the setting of the bonding agent under pressure.

Another advantage of the present invention is that an embodiment of a laminated log consists in roughly cut wood elements glued together with a solid insulated material such as expanded polystyrene or the like. When all elements are simultaneously glued under pressure, the rough laminated log is run through a cutting device which faces, preferably simultaneously, the log on the four (4) surfaces thereof, which gives the log its rounded shape and/or the complementary pair(s) of longitudinal tongue and groove joinery, amongst surface characteristics.

Still another advantage of the present invention is the relatively simple method of manufacturing of the laminated logs, at a relatively low cost.

Yet another advantage of the present invention is that the laminated log, because of its relatively thick internal and external wooden plank layers, is a structural element of a building wall made out of these logs stacked on top of one another, in a staggered manner (similarly to building bricks).

A further advantage of the present invention is that the method for manufacturing a laminated log includes the step of simultaneously applying pressure to all layers of the entire laminated log during the setting of the bonding agent, or glue, between all adjacent layers at a same time.

According to an aspect of the present invention there is provided a method for manufacturing a laminated log, said laminated log defining along a longitudinal axis thereof an interior surface, an opposite exterior surface, and first and second intermediate surfaces extending between said interior and exterior surfaces, said method comprising the steps of:

-   -   forming a laminate having a solid insulating material layer         located between an internal wooden plank layer and an external         wooden plank layer, with a plurality of compression limiter         members being located between said internal and external plank         layers inside respective through holes extending through said         solid insulating material layer between said internal and         external wooden plank layers, said through holes being spaced         apart from one another along said longitudinal axis of said         laminated log;     -   applying a layer of bonding agent between each adjacent said         layers; and     -   applying and maintaining pressure against said interior and         exterior surfaces of said laminate during a predetermined time         duration and within controlled environmental temperature and         humidity level ranges to allow setting of said bonding agent         layers and adhesion of each said layer to adjacent said layers.

In one embodiment, the method further includes the step of facing at least one of said interior, exterior, and first and second intermediate surfaces.

According to another aspect of the present invention there is provided a laminated log manufactured according to the method as hereinabove detailed.

Other objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided herein, with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects and advantages of the present invention will become better understood with reference to the description in association with the following Figures, in which similar references used in different Figures denote similar components, wherein;

FIG. 1 is a top perspective view of a rough laminated log in accordance with an embodiment of the present invention;

FIG. 2 is an exploded top perspective view of the embodiment of FIG. 1;

FIG. 3 is a longitudinal section view of the embodiment of FIG. 1 taken along line 3-3 of FIG. 1;

FIG. 4 is a transversal section view of the embodiment of FIG. 1 taken along line 4-4 of FIG. 3; and

FIG. 5 is a block diagram showing a method for manufacturing the embodiment of FIG. 1 in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the annexed drawings the preferred embodiment of the present invention will be herein described for indicative purpose and by no means as of limitation.

Referring to FIGS. 1 through 4, there is shown a laminated log in accordance with an embodiment 10 of the present invention used for building house walls and the like, and manufactured in accordance with an embodiment of the method described herein below. The log 10 defines, along a longitudinal axis 11 thereof, an interior surface 12, an opposite exterior surface 14, and first 16 and second 18 intermediate surfaces extending between the interior 12 and exterior 14 surfaces. The log 10 is typically formed of a laminate having a solid insulating material layer 20 located between an internal wooden plank layer 30 and an external wooden plank layer 40, with a plurality of compression limiter members 26 being located between the internal 30 and external 40 plank layers inside respective through holes 24 extending through said solid insulating material layer 20 between the internal 30 and external 40 wooden plank layers. The through holes 24 are, preferably equally, spaced apart from one another along the longitudinal axis 11 of the laminated log 10. The compression limiter members 26, being typically made out of any wooden structure, are typically sized to control a compression rate of the solid insulating material layer 20 since they directly contact the internal and external wooden plank layers, and are preferably of a length extending between the internal 30 and external 40 wooden plank layers substantially slightly less (by typically about 0.125 inch) than or equal to the thickness of the solid insulating material layer 20, as seen in FIGS. 3 and 4. By being 0.125 inch shorter than the thickness of the solid insulating material layer 20, this ensure a slight compression of the solid insulating material layer 20 to enable proper adhesion of the solid insulating material layer 20 to the adjacent internal 30 and external 40 wooden plank layers. Preferably, each compression limiter member 26 substantially entirely fills the respective through hole 24 it sits into.

Typically, the solid insulating material layer 20 includes one layer 22 of anyone of a number of solid insulating materials including, but not limited to, polystyrene, polyurethane, polyisocyanurate and the like. Each one of the internal 30 and external 40 plank layers typically includes at least one, preferably two (2) superposed adjacent wooden planks 32 and 42, 44, respectively, with a layer of bonding agent there between, in order to ensure structural and dimensional stability of the log 10. These wooden planks 32, 42, 44 are typically made out of natural wood such as spruce, fir, pine and the like.

A layer of bonding agent (not shown) is applied between each adjacent ones of the layers 20, 30, 40. The bonding agent used to bond, at the same time, all elements together and ensure proper adhesion there between over wide ranges of temperature and humidity level there across, can be of different form and is preferably a liquid polyurethane glue or the like. The setting of the bonding agent is typically done under controlled environmental conditions, such as pressure P level range, temperature range and/or humidity level range, for a predetermined time duration range, depending on the bonding agent being used. Preferably, the controlled environmental conditions required for the liquid polyurethane glue are ambient ranges of temperature and humidity levels. Also, the pressure P. preferably uniform over the entire interior 12 and exterior 14 surfaces (as shown in FIGS. 1 and 2), is typically within a range varying from about 50 psi (pound per square inch) to about 120 psi, and preferably about 100 psi.

After the layers 20, 30, 40 are bonded together, at least one, preferably all of the surfaces 12, 14, 16, 18 of the rough laminate 10 are, preferably simultaneously, faced to provide either straight, rounded (typically convex as the external wooden layer 42 defining the exterior surface 12 of FIG. 4 to simulate the look of a natural wooden log), or machined (as the first 16 and second 18 surfaces of FIG. 4) surfaces of a finished laminated log 10. The machined first 16 and second 18 intermediate surfaces typically include at least one, and preferably two (2) respective complementary pairs of longitudinal tongue and groove joinery thereon. These pairs of longitudinal tongue and groove joinery are used for proper alignment of the adjacent laminated logs 10 for the construction of walls of buildings like houses.

An embodiment of a method for manufacturing the laminated log 10 is also part of the present invention, as shown in the diagram of FIG. 5. Accordingly, the method typically includes the steps of: 1) forming a laminate 10 having a solid insulating material layer 20 located between an internal wooden plank layer 30 and an external wooden plank layer 40, with a plurality of compression limiter members 26 being located between the internal 30 and external 40 plank layers inside respective through holes 24 extending through the solid insulating material layer 20 and being spaced apart from one another along a longitudinal axis 11 of the laminated log 10; 2) applying a layer of bonding agent between each adjacent said layers 20, 30, 40; and 3) applying and maintaining pressure P against the interior 12 and exterior 14 surfaces of the laminate 10 during a predetermined time duration and within controlled environmental temperature and humidity level ranges to allow setting of the bonding agent layers and adhesion of each layer 20, 30, 40 to adjacent said layers, simultaneously, all at the same time.

When the pressure P is applied, a plurality of laminated logs 10, 10′ may be simultaneously pressurized as schematically illustrated in FIG. 1 with adjacent logs 10′ above and below the laminated log 10.

Typically, the method further includes the step of facing at least one and preferably simultaneously facing at least two of the interior 12, exterior 14, and first 16 and second 18 intermediate surfaces of the laminated log 10. Such facing is typically made with the laminated log 10 being run into a cutting device such as a molder or the like.

Obviously, although not shown, only the interior or both interior 12 and exterior 14 surfaces can be rounded, depending on the desired look of the specific laminated log walls.

Although the present invention has been described with a certain degree of particularity, it is to be understood that the disclosure has been made by way of example only and that the present invention is not limited to the features of the embodiments described and illustrated herein, but includes all variations and modifications within the scope of the invention as hereinafter claimed. 

I claim:
 1. A method for manufacturing a laminated log, said laminated log defining along a longitudinal axis thereof an interior surface, an opposite exterior surface, and first and second intermediate surfaces extending between said interior and exterior surfaces, said method comprising the steps of: forming a laminate having a solid insulating material layer located between an internal wooden plank layer and an external wooden plank layer, with a plurality of compression limiter members being located between said internal and external plank layers inside respective through holes extending through said solid insulating material layer between said internal and external wooden plank layers, said through holes being spaced apart from one another along said longitudinal axis of said laminated log; applying a layer of bonding agent between each adjacent said layers; and applying and maintaining pressure against said interior and exterior surfaces of said laminate during a predetermined time duration and within controlled environmental temperature and humidity level ranges to allow setting of said bonding agent layers and adhesion of each said layer to adjacent said layers.
 2. The method of claim 1, wherein, in the step of forming a laminate, said plurality of compression limiter members are sized to control a compression rate of said solid insulating material layer during the step of applying and maintaining pressure.
 3. The method of claim 2, wherein, in the step of forming a laminate, said plurality of compression limiter members are of a length extending between said internal and external wooden plank layers substantially slightly less than or equal to a thickness of said solid insulating material layer.
 4. The method of claim 3, wherein, in the step of forming a laminate, each one of the plurality of compression limiter members substantially entirely fills the respective one of said through holes.
 5. The method of claim 1, wherein, in the step of forming a laminate, said through holes are substantially equally spaced apart from one another along said longitudinal axis of said laminated log.
 6. The method of claim 1, further including the step of facing at least one of said interior, exterior, and first and second intermediate surfaces.
 7. The method of claim 6, wherein the step of facing includes facing at least two of said interior, exterior, and first and second intermediate surfaces.
 8. The method of claim 7, wherein the step of facing includes simultaneously facing said at least two of said interior, exterior, and first and second intermediate surfaces.
 9. The method of claim 1, wherein the step of forming a laminate includes forming a laminate wherein at least one of said internal and external wooden plank layers includes at least two superposed adjacent wooden planks with a layer of bonding agent therebetween.
 10. The method of claim 9, wherein the step of forming a laminate includes forming a laminate wherein each said internal and external wooden plank layer includes at least two superposed adjacent wooden planks with a layer of bonding agent therebetween.
 11. The method of claim 6, wherein the step of facing includes forming at least one complementary pair of longitudinal tongue and groove joinery on respective said first and second intermediate surfaces.
 12. The method of claim 6, wherein the step of facing includes forming a rounded surface on at least one of said interior and exterior surfaces.
 13. The method of claim 1, wherein the step of applying and maintaining pressure includes applying and maintaining uniform pressure against said entire interior and exterior surfaces of said laminate.
 14. The method of claim 13, wherein, in the step of applying and maintaining pressure, the uniform pressure being within a range varying from about 50 psi to about 120 psi.
 15. The method of claim 14, wherein, in the step of applying and maintaining pressure, the uniform pressure being about 100 psi.
 16. A laminated log manufactured according to the method of claim
 1. 